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Nick F

Senior forecaster
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Everything posted by Nick F

  1. Although far from resolved past day 5/6, as the trough extends south across western Europe later next week - 00z EC barely gets sub -5C T850s past NW Scotland, while pumping a lot of warm air into NE Europe. You really need to see well below -5C T850s in a maritime flow for snow at lower levels, drier continental flows not so much, as DPs lower. Ideally would like to see the trough axis later next week/weekend further east to get that direct arctic feed, but this not being flagged as happening for now - thanks to the big blocking high to the east. The 00z EC is a mild outlier towards the
  2. 12z UKMO T+144 looks further east with the deep trough axis extending south over UK next Thursday compared to other models, so an arctic northerly more likely over UK rather than staying out west over the Atlantic ... pity we can't see subsequent timeframes with T850s!
  3. 12z GFS, polar front jet positioned a fair bit futher south and west of the UK than 06z 1st weekend of December. As a result, we have some cold air to play with and we're into slider low territory as Atlantic lows come up against blocking to the east.
  4. Quite a potent storm system developing over eastern U.S. early next week as split northern and southern streams over the U.S. merge, the surge north of Caribbean airmass ahead of the storm colliding with cold polar air swinging in from behind the system likely to stoke up the jet stream downstream over the NW Atlantic next week, hence why the models are trying to flatten the upper flow out over the Atlantic towards NW Europe late next week. But, 06z GFS is progressive with moving the east coast storm system NE towards Greenland later next week compared to 00z GFS and 00z EC ops, whi
  5. Not a bad 06z GFS given the likely way forward now, agreed on by the models, of the polar trough extending SE from Greenland to western Europe between days 6 and 8. 00z EC the worst case scenario with the trough disruption into a cut-off low by keeping the low close to the west of the UK. GFS has the upper low over Iberia and extending into western Med, which allows ridging to build over the top and keep us in an easterly flow, which could turn colder. Which model should we have more faith in? As it appears, reading some tweets by US mets last few days, EC may be having some issues with m
  6. Waiting for a deep cold northerly or easterly to appear in the UK at the moment: Joking aside, the CPC 8-14 day 500mb outlook gives some optimism... Good things could happen for coldies with that look, particularly good to see the TPV displaced toward Siberia still.
  7. Looked like it was an epic 12z GFS shaping up as it was rolling out ... but we miss the deep cold thrust going into Scandi to east. However, an injection of deep cold direct from the arctic into E/NE Europe and NW Russia not a bad thing IMO, should pressure build back to the NE to bring an easterly again, it would source this pool of deeper cold dropping down from the TPV and obviously increase the chance for a BFTE. However, pull the lobe of the TPV a little further west by 500 miles as it drops south, then we could see a bitter northerly. Should we have to sit it out with high pres
  8. A long way off, 7 days away, but nice cold pool moving west over UK on 18z GFS, -7C T850s across southern England and Wales, be cold enough for some snow flurries. Of course take with a pinch of salt, but nice to see...
  9. Excellent for pulling in mild air from southern Europe? Can see it leading to an interesting evolution further down the line with the very blocked look, but only if we can source in some deep cold from somewhere.
  10. 12z EC shows the dangers of polar upper trough digging south too far west. Yes the trough could disrupt into a cut-off low merging with troughing over SW Europe to allow for an easterly as high pressure extends over the top, but the source is a not particularly cold at depth airmass over eastern Europe. Could do with a direct arctic feed.
  11. Not very often we get high reward for high risk. 00z EC control shows the dangers of the said trough axis digging south too far west. It always seems we are chasing carrots at the end of the stick every winter, so many hurdles to overcome, be nice for once these teases in the unreliable time frames come off or something cold and wintry to pop up out of the blue. But, we are in a reasonable position as we head into early winter, plenty of blocking showing up and a TPV that's not connected to the SPV while displacing towards Siberia. At least the EC weeklies don't look too terrib
  12. Seems to be some reasonable consistency in the last 3 EC deterministic runs to pull a lobe of the trop PV S and SE towards northern Europe while upper ridge amplifies N over the far NW Atlantic early few days of December - which could trigger an arctic-sourced northerly. But the GFS not hinting at this yet. GEFS mean in the medium range and yesterday’s CPC 8 to 14 Day 500mb Outlook points to Canada looking blocked with the TPV displaced over towards Siberia, while energy going into STJ over southern states forming a trough over southeastern US which teleconnects to NW Atlantic ridg
  13. Trigger shortwave or scuppered by shortwave? Day 10 EC leaves us on a cliffhanger
  14. A look at how the Covid-19 pandemic has reduced some of the different types of weather observations used by Numerical Weather Prediction (NWP) models View the full blog here
  15. Seems to be ensemble support now for mid-latitude ridging developing over UK as we end the weekend and head through early next week - as ridge to the NE and Azores ridge join forces, which is fine, as it will bring some chilly days and cold nights helped by a continental feed in the south. In the extended model outlook, the Scandi-Ural block looks to remain a formidable force as we head into early December in ensemble guidance - and will surely help longer term prospects with anticyclonic wave breaking over the NE Atlantic as troughs from the TPV try to push in towards NW Europe.
  16. TPV retograding away from our side of the northern Hemisphere across the north Pole, looping the 12z EC NH charts, certainly aiding the +ve heights to the NE being maintained and hopefully stretching our way. Now if the TPV can stay away that would be good prospects for growing surface and eventually upper cold as we head into early December.
  17. Not a mild outlook if you take the 00z EC ensemble average T2m for London
  18. EPS means at T+300 could be worse, at least there are low heights over SW Europe/western Med and +ve height anomaly over Scandi. With weak (compared to the norm) troughing signal in the means to our west and NW. Trouble is, there is no strong signal for Scandi block to extend far enough west in the guidance, due to the pressure imposed by the TPV over Greenland extending out over the NE Atlantic, plus lack of jet energy diverting into SW Europe - which with time comes cut-off with all the jet energy going NE. Still, there is a great deal of uncertainty over how long the blockin
  19. Seems to be a growing consensus from 00z GFS/EC and their ensemble means in holding back a full on return of mobility next week and following weekend, due to trough disruption west of Iberia Weds/Thurs, which the models often struggle with, forcing high pressure/heights to build over NW Europe as upper low closes off near Iberia. EPS MEAN T+180 Whether this delays an inevitable return to Atlantic mobility or building heights close to the east continues the stalling of upper troughing/low heights pushing in from the west - remains to be seen. Bit too far off in time for the mod
  20. 06z GFS op still not buying the trough disruption to the W and SW over the Atlantic the Euro models are keen on ...
  21. Oh no, not another Scandi high / easterly wild goose chase from the EC! Joking aside, models digress with trough disruption or lack of as early as T+144 ... 00z EC and UKMO want to disrupt trough to the west of western Europe out over the Atlantic ... EC op goes on to build a high over UK as low closes off west of Iberia, high then drifts east toward Scandi/Baltic area. EC T+144 UKMO T+144 Whilst GFS keeps the upper trough intact and moves it east, so we are kept in mobile westerly regime. GFS T+144 Until models agree on trough disruption ou
  22. Aye, saw someone tweet that the long range EC was showing a SSW in January other day, if we can get that, then perhaps we can avoid a winter cancel in January and February.
  23. I actually think there's a greater chance of cold/wintry weather this side of the New Year. Current canonical La Nina with colder waters in the eastern Pacific compared to the central Pac, that looks to persist into Dec, tends to favour high latitude blocking / -NAO in late Nov/December if the trop PV is still weak. Think 2010, with similar East Pacific La Nina, but nowhere near as extreme. January/February 2021 probably milder, as the La Nina colder waters transfer further west into Modoki/central Pacific, forcing patterns to readjust and a strenghtening TPV to take hold forcing a +NAO.
  24. Good grief 06z, need to work on the T850s but still a chilly continental flow day 10 The 00z GEFS mean hinting at Atlantic wave- breaking against blocking high to the NE too, but further out, the latest op just brings it forward
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